What Is… An Ethnic Matching Study?

The details of a brand new study land on my desk, and I prepare myself to start researching a new (to me) and particularly nasty-sounding condition called Trigeminal Neuralgia. But there’s something even more unusual about this study: it’s a type of clinical trial called an ethnic matching study.

For this trial, our volunteers will be split into 3 groups of Caucasian volunteers and 3 groups of Japanese volunteers. The idea is that for every Japanese volunteer who enrols, we have a Caucasian volunteer to match them; so if a Japanese woman weighing 51kg checks in, we must also check-in a Caucasian woman weighing around 51kg on the next group, so that we can compare their details as closely as possible.

Now, I might’ve mentioned this already – but I’m NOT a scientist! My gut tells me there must be a very good reason for us to introduce such a complicated study design. So I decide to find out!

I start by learning a little more about Trigeminal Neuralgia (TN), and almost straight away I wish I hadn’t.

TN is a form of chronic pain affecting the trigeminal nerve – the nerve which controls sensitivity in the face. It starts above and behind the ear and has branches stretching across the jaw, cheekbone and eye socket. If the protective sheathing around this nerve is damaged, patients can experience pain so intense that TN has been ‘fondly’ nicknamed ‘The Suicide Disease’. That’s right. People have committed suicide rather than experience more of the pain. It’s that bad.

Shuddering, I try and find out what a patient’s alternatives to suicide are. I’m pretty sure this is not a job for paracetamol or ibuprofen.

I’m not really comforted to learn that one option is using radiation or surgery to permanently damage the trigeminal nerve. This method effectively removes the source of the pain, but can also result in facial numbness.

The other option is to take anti-convulsant drugs which block pain signals from the nerve. These are the most effective and least invasive option for TN patients. They are, quite literally, a lifeline. But they aren’t perfect.

In very rare cases, some anti-convulsants can trigger a serious skin condition called Stevens-Johnson Syndrome, which can be lethal if not diagnosed and treated quickly. To reiterate, this is a very rare side effect, affecting as few as 1 in 10,000 patients. However, it is most often found in patients of Asian descent.

This isn’t the only example of patients from different ethnic groups reacting differently to medications. For instance, warfarin, which is commonly used to treat high blood pressure, is prescribed in different doses to Black, White and Asian patients, because each group metabolizes the drug at different rates.

In this study, we are testing a new anti-convulsant. Well, newish, to be more precise. The drug has already passed safety testing in healthy volunteers, and it has been found to be effective in treating patients with trigeminal neuralgia. And while this is all extremely positive, we need to closely scrutinize the effect of the drug on our Japanese volunteers to ensure that Asian patients are not being exposed to a higher risk of serious side effects. Clever, eh?

This clinical trial is a vital stage in bringing a new treatment, and new hope, to patients who need it. If you’d like to be a part of it, and you can commit to spending 5 nights in our Leeds clinic, apply to become a Covance paid volunteer.